how to improve query performance

Querying, adding, modifying, and deleting databases are important factors that affect web application performance indicators. The following are some common suggestions to improve query performance. Querying, adding, modifying, and deleting databases

ORACLE DBA face Test setOne: SQL tuning class1 Enumerate several table connection wayssuch as connection, non-equal connection, self connection, outer connection (left, right, full)2 How to view SQL execution plan without the help of a third-party

performance counters for loadrunner monitoring today, I put up some of my counters and their threshold requirements, etc., which are for my Windows operating system, C/s structure of SQL Server database and Web platform. NET product test some of

Http://www.cnblogs.com/zhijianliutang/archive/2012/10/28/2743722.htmlWhen we have a larger amount of data, we need to split the large tables into smaller tables, and queries that only access departmental data can run faster, the rationale being that

ObjectiveIn this section we continue to talk about index knowledge, before we clustered index, nonclustered index and overlay index, there is also a filter index, through the index filter we can also improve query performance, short content,

BKJIA Summary: in the previous article, we have read several major factors in DB2 performance optimization. This time, let's take a look at DB2 performance issues and see how these problems are classified, what is an analysis idea. DML performance

SQL Server focuses on filtering indexes and SQL Server Indexes Preface In this section, we will continue to talk about index knowledge. We have clustered indexes, non-clustered indexes, and covered indexes. Here we also have a filter index, which

This article mainly describes the DB2 materialized query table, and also introduces MQT, summary table (summary), and staging table. To better describe it, we use some practical examples to show how to create and use materialized query tables. The

Create indexed fields such as data storage that are frequently referenced by query criteria. This pattern can improve query performance by allowing applications to locate data more quickly to retrieve data from the datastore.Background and

Through the previous two articles we basically learned how to combine the execution plan to analyze the performance of a SQL statement, since there is a performance problem has been found, the next is how to optimize the query to improve query

Cloud computing design model (12)-index table modelFields such as data storage that are frequently referenced by query conditions that have created indexes. This mode allows applications to quickly locate data and retrieve data from data storage to

Cloud computing design model (14)-Materialized view modeData is formatted in the opinion that data is pre-filled in one or more data storages, which is not conducive to the required query operations. This mode can help you efficiently query and

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I. SQL tuning class1: List several table Connection MethodsHash join/merge join/nest loop (cluster join)/index join 2: How to view SQL Execution plans without using third-party toolsSet autot on Explain plan set statement_id = & item_id for &

A dba questionNote: You can select and answer the following questions based on your own situation. You do not have to answer all the questions. You can also directly contact the interviewer to answer the questions without answering them. I. SQL

2014-08-22 BaoxinjianI. Summary 1. Partition table:As the table continues to grow, it is more difficult to maintain the new record's increase, find, delete, and so on (DML). For a very large table in a database, you can simplify the management

Original: SQL Server Tuning series advanced (How to index tuning)ObjectiveIn the previous article we analyzed the role of statistical information in the database, and we have learned how the database uses statistics to control the distribution of

Creating indexes on large tables is very cautious, bad indexes can cause performance problems, but well-designed indexes are dozens of times times more likely to improve query performance, and there are several issues to be aware of when creating

Unique indexIf the primary key is not set to a clustered index when it is created, it must be a unique nonclustered index. In fact, the unique index, the name Incredibles, is that it requires the value on that column to be unique. A unique index

Oracle Database Index 1 index basic concept index is a data object used to accelerate data access. Rational Use of indexes can greatly reduce the number of I/O operations, thus improving data access performance. Single-Column index: an index created